Move many zuul strings to FilterConstants.

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/filters/post/SendErrorFilter.java

@@ -20,24 +20,29 @@ import javax.servlet.RequestDispatcher;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
-import com.netflix.zuul.exception.ZuulException;
-import lombok.extern.apachecommons.CommonsLog;
-
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.cloud.netflix.zuul.util.ZuulRuntimeException;
 import org.springframework.util.ReflectionUtils;
+import org.springframework.util.StringUtils;
 
 import com.netflix.zuul.ZuulFilter;
 import com.netflix.zuul.context.RequestContext;
-import org.springframework.util.StringUtils;
+import com.netflix.zuul.exception.ZuulException;
+
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.ERROR_TYPE;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.SEND_ERROR_FILTER_ORDER;
 
 /**
+ * Error {@link ZuulFilter} that forwards to /error (by default) if {@link RequestContext#getThrowable()} is not null.
+ *
  * @author Spencer Gibb
  */
 //TODO: move to error package in Edgware
-@CommonsLog
 public class SendErrorFilter extends ZuulFilter {
 
+	private static final Log log = LogFactory.getLog(SendErrorFilter.class);
 	protected static final String SEND_ERROR_FILTER_RAN = "sendErrorFilter.ran";
 
 	@Value("${error.path:/error}")
@@ -45,12 +50,12 @@ public class SendErrorFilter extends ZuulFilter {
 
 	@Override
 	public String filterType() {
-		return "error";
+		return ERROR_TYPE;
 	}
 
 	@Override
 	public int filterOrder() {
-		return 0;
+		return SEND_ERROR_FILTER_ORDER;
 	}
 
 	@Override

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/filters/post/SendResponseFilter.java

@@ -16,16 +16,19 @@
 
 package org.springframework.cloud.netflix.zuul.filters.post;
 
-import lombok.extern.apachecommons.CommonsLog;
-
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.util.List;
 import java.util.zip.GZIPInputStream;
+
 import javax.servlet.http.HttpServletResponse;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import org.springframework.util.ReflectionUtils;
+
 import com.netflix.config.DynamicBooleanProperty;
 import com.netflix.config.DynamicIntProperty;
 import com.netflix.config.DynamicPropertyFactory;
@@ -36,12 +39,22 @@ import com.netflix.zuul.constants.ZuulHeaders;
 import com.netflix.zuul.context.RequestContext;
 import com.netflix.zuul.util.HTTPRequestUtils;
 
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.POST_TYPE;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.ROUTING_DEBUG_KEY;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.SEND_RESPONSE_FILTER_ORDER;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.X_ZUUL_DEBUG_HEADER;
+
 /**
+ * Post {@link ZuulFilter} that writes responses from proxied requests to the current response.
+ *
  * @author Spencer Gibb
+ * @author Dave Syer
+ * @author Ryan Baxter
  */
-@CommonsLog
 public class SendResponseFilter extends ZuulFilter {
 
+	private static final Log log = LogFactory.getLog(SendResponseFilter.class);
+
 	private static DynamicBooleanProperty INCLUDE_DEBUG_HEADER = DynamicPropertyFactory
 			.getInstance()
 			.getBooleanProperty(ZuulConstants.ZUUL_INCLUDE_DEBUG_HEADER, false);
@@ -74,12 +87,12 @@ public class SendResponseFilter extends ZuulFilter {
 	
 	@Override
 	public String filterType() {
-		return "post";
+		return POST_TYPE;
 	}
 
 	@Override
 	public int filterOrder() {
-		return 1000;
+		return SEND_RESPONSE_FILTER_ORDER;
 	}
 
 	@Override
@@ -201,13 +214,13 @@ public class SendResponseFilter extends ZuulFilter {
 		HttpServletResponse servletResponse = context.getResponse();
 		if (INCLUDE_DEBUG_HEADER.get()) {
 			@SuppressWarnings("unchecked")
-			List<String> rd = (List<String>) context.get("routingDebug");
+			List<String> rd = (List<String>) context.get(ROUTING_DEBUG_KEY);
 			if (rd != null) {
 				StringBuilder debugHeader = new StringBuilder();
 				for (String it : rd) {
 					debugHeader.append("[[[" + it + "]]]");
 				}
-				servletResponse.addHeader("X-Zuul-Debug-Header", debugHeader.toString());
+				servletResponse.addHeader(X_ZUUL_DEBUG_HEADER, debugHeader.toString());
 			}
 		}
 		List<Pair<String, String>> zuulResponseHeaders = context.getZuulResponseHeaders();
@@ -237,4 +250,4 @@ public class SendResponseFilter extends ZuulFilter {
 		return value <= Integer.MAX_VALUE && value >= Integer.MIN_VALUE;
 	}
 
-}
+}
\ No newline at end of file

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/filters/pre/DebugFilter.java

@@ -25,7 +25,13 @@ import com.netflix.zuul.ZuulFilter;
 import com.netflix.zuul.constants.ZuulConstants;
 import com.netflix.zuul.context.RequestContext;
 
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.DEBUG_FILTER_ORDER;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.PRE_TYPE;
+
 /**
+ * Pre {@link ZuulFilter} that sets {@link RequestContext} debug attributes to true if
+ * the "debug" request parameter is set.
+ *
  * @author Spencer Gibb
  */
 public class DebugFilter extends ZuulFilter {
@@ -38,12 +44,12 @@ public class DebugFilter extends ZuulFilter {
 
 	@Override
 	public String filterType() {
-		return "pre";
+		return PRE_TYPE;
 	}
 
 	@Override
 	public int filterOrder() {
-		return 1;
+		return DEBUG_FILTER_ORDER;
 	}
 
 	@Override

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/filters/pre/FormBodyWrapperFilter.java

@@ -20,10 +20,6 @@ import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.lang.reflect.Field;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Set;
-import java.util.Map.Entry;
 
 import javax.servlet.ServletInputStream;
 import javax.servlet.ServletRequest;
@@ -46,8 +42,13 @@ import com.netflix.zuul.context.RequestContext;
 import com.netflix.zuul.http.HttpServletRequestWrapper;
 import com.netflix.zuul.http.ServletInputStreamWrapper;
 
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.FORM_BODY_WRAPPER_FILTER_ORDER;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.PRE_TYPE;
+
 /**
- * @author Spencer Gibb
+ * Pre {@link ZuulFilter} that parses form data and reencodes it for downstream services
+ *
+ * @author Dave Syer
  */
 public class FormBodyWrapperFilter extends ZuulFilter {
 
@@ -69,12 +70,12 @@ public class FormBodyWrapperFilter extends ZuulFilter {
 
 	@Override
 	public String filterType() {
-		return "pre";
+		return PRE_TYPE;
 	}
 
 	@Override
 	public int filterOrder() {
-		return -1;
+		return FORM_BODY_WRAPPER_FILTER_ORDER;
 	}
 
 	@Override

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/filters/pre/Servlet30RequestWrapper.java

@@ -20,6 +20,9 @@ import com.netflix.zuul.http.HttpServletRequestWrapper;
 
 import javax.servlet.http.HttpServletRequest;
 
+/**
+ * A Servlet 3.0 compliant wrapper.
+ */
 class Servlet30RequestWrapper extends HttpServletRequestWrapper {
 	private HttpServletRequest request;
 

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/filters/pre/Servlet30WrapperFilter.java

@@ -28,7 +28,12 @@ import com.netflix.zuul.ZuulFilter;
 import com.netflix.zuul.context.RequestContext;
 import com.netflix.zuul.http.HttpServletRequestWrapper;
 
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.PRE_TYPE;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.SERVLET_30_WRAPPER_FILTER_ORDER;
+
 /**
+ * Pre {@link ZuulFilter} that wraps requests in a Servlet 3.0 compliant wrapper.
+ * Zuul's default wrapper is only Servlet 2.5 compliant.
  * @author Spencer Gibb
  */
 public class Servlet30WrapperFilter extends ZuulFilter {
@@ -49,12 +54,12 @@ public class Servlet30WrapperFilter extends ZuulFilter {
 
 	@Override
 	public String filterType() {
-		return "pre";
+		return PRE_TYPE;
 	}
 
 	@Override
 	public int filterOrder() {
-		return -2;
+		return SERVLET_30_WRAPPER_FILTER_ORDER;
 	}
 
 	@Override

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/filters/pre/ServletDetectionFilter.java

@@ -26,6 +26,9 @@ import com.netflix.zuul.context.RequestContext;
 import com.netflix.zuul.http.HttpServletRequestWrapper;
 import com.netflix.zuul.http.ZuulServlet;
 
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.PRE_TYPE;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.SERVLET_DETECTION_FILTER_ORDER;
+
 /**
  * Detects whether a request is ran through the {@link DispatcherServlet} or {@link ZuulServlet}.
  * The purpose was to detect this up-front at the very beginning of Zuul filter processing
@@ -41,7 +44,7 @@ public class ServletDetectionFilter extends ZuulFilter {
 
 	@Override
 	public String filterType() {
-		return "pre";
+		return PRE_TYPE;
 	}
 
 	/**
@@ -50,7 +53,7 @@ public class ServletDetectionFilter extends ZuulFilter {
 	 */
 	@Override
 	public int filterOrder() {
-		return -3;
+		return SERVLET_DETECTION_FILTER_ORDER;
 	}
 
 	@Override

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/filters/route/RestClientRibbonCommand.java

@@ -22,6 +22,7 @@ import java.net.URI;
 import java.util.List;
 import org.springframework.cloud.netflix.zuul.filters.ZuulProperties;
 import org.springframework.cloud.netflix.zuul.filters.route.support.AbstractRibbonCommand;
+import org.springframework.http.HttpMethod;
 import org.springframework.util.MultiValueMap;
 import com.netflix.client.config.IClientConfig;
 import com.netflix.client.http.HttpRequest;
@@ -68,7 +69,7 @@ public class RestClientRibbonCommand extends AbstractRibbonCommand<RestClient, H
 	protected HttpRequest createRequest() throws Exception {
 		final InputStream requestEntity;
 		// ApacheHttpClient4Handler does not support body in delete requests
-		if (getContext().getMethod().equalsIgnoreCase("DELETE")) {
+		if (getContext().getMethod().equalsIgnoreCase(HttpMethod.DELETE.toString())) {
 			requestEntity = null;
 		} else {
 			requestEntity = this.context.getRequestEntity();

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/filters/route/RibbonRoutingFilter.java

@@ -24,6 +24,8 @@ import java.util.Map;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import org.springframework.cloud.netflix.ribbon.support.RibbonRequestCustomizer;
 import org.springframework.cloud.netflix.zuul.filters.ProxyRequestHelper;
 import org.springframework.cloud.netflix.zuul.util.ZuulRuntimeException;
@@ -37,11 +39,24 @@ import com.netflix.zuul.ZuulFilter;
 import com.netflix.zuul.context.RequestContext;
 import com.netflix.zuul.exception.ZuulException;
 
-import lombok.extern.apachecommons.CommonsLog;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.REQUEST_ENTITY_KEY;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.RETRYABLE_KEY;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.RIBBON_ROUTING_FILTER_ORDER;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.ROUTE_TYPE;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.SERVICE_ID_KEY;
 
-@CommonsLog
+/**
+ * Route {@link ZuulFilter} that uses Ribbon, Hystrix and pluggable http clients to send requests.
+ * ServiceIds are found in the {@link RequestContext} attribute {@link org.springframework.cloud.netflix.zuul.filters.support.FilterConstants#SERVICE_ID_KEY}.
+ *
+ * @author Spencer Gibb
+ * @author Dave Syer
+ * @author Ryan Baxter
+ */
 public class RibbonRoutingFilter extends ZuulFilter {
 
+	private static final Log log = LogFactory.getLog(RibbonRoutingFilter.class);
+
 	protected ProxyRequestHelper helper;
 	protected RibbonCommandFactory<?> ribbonCommandFactory;
 	protected List<RibbonRequestCustomizer> requestCustomizers;
@@ -67,18 +82,18 @@ public class RibbonRoutingFilter extends ZuulFilter {
 
 	@Override
 	public String filterType() {
-		return "route";
+		return ROUTE_TYPE;
 	}
 
 	@Override
 	public int filterOrder() {
-		return 10;
+		return RIBBON_ROUTING_FILTER_ORDER;
 	}
 
 	@Override
 	public boolean shouldFilter() {
 		RequestContext ctx = RequestContext.getCurrentContext();
-		return (ctx.getRouteHost() == null && ctx.get("serviceId") != null
+		return (ctx.getRouteHost() == null && ctx.get(SERVICE_ID_KEY) != null
 				&& ctx.sendZuulResponse());
 	}
 
@@ -113,8 +128,8 @@ public class RibbonRoutingFilter extends ZuulFilter {
 			context.setChunkedRequestBody();
 		}
 
-		String serviceId = (String) context.get("serviceId");
-		Boolean retryable = (Boolean) context.get("retryable");
+		String serviceId = (String) context.get(SERVICE_ID_KEY);
+		Boolean retryable = (Boolean) context.get(RETRYABLE_KEY);
 
 		String uri = this.helper.buildZuulRequestURI(request);
 
@@ -182,7 +197,7 @@ public class RibbonRoutingFilter extends ZuulFilter {
 		InputStream requestEntity = null;
 		try {
 			requestEntity = (InputStream) RequestContext.getCurrentContext()
-					.get("requestEntity");
+					.get(REQUEST_ENTITY_KEY);
 			if (requestEntity == null) {
 				requestEntity = request.getInputStream();
 			}

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/filters/route/SendForwardFilter.java

@@ -23,7 +23,15 @@ import org.springframework.util.ReflectionUtils;
 import com.netflix.zuul.ZuulFilter;
 import com.netflix.zuul.context.RequestContext;
 
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.FORWARD_TO_KEY;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.ROUTE_TYPE;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.SEND_FORWARD_FILTER_ORDER;
+
 /**
+ * Route {@link ZuulFilter} that forwards requests using the {@link RequestDispatcher}.
+ * Forwarding location is located in the {@link RequestContext} attribute {@link org.springframework.cloud.netflix.zuul.filters.support.FilterConstants#FORWARD_TO_KEY}.
+ * Useful for forwarding to endpoints in the current application.
+ *
  * @author Dave Syer
  */
 public class SendForwardFilter extends ZuulFilter {
@@ -32,18 +40,18 @@ public class SendForwardFilter extends ZuulFilter {
 
 	@Override
 	public String filterType() {
-		return "route";
+		return ROUTE_TYPE;
 	}
 
 	@Override
 	public int filterOrder() {
-		return 500;
+		return SEND_FORWARD_FILTER_ORDER;
 	}
 
 	@Override
 	public boolean shouldFilter() {
 		RequestContext ctx = RequestContext.getCurrentContext();
-		return ctx.containsKey("forward.to")
+		return ctx.containsKey(FORWARD_TO_KEY)
 				&& !ctx.getBoolean(SEND_FORWARD_FILTER_RAN, false);
 	}
 
@@ -51,7 +59,7 @@ public class SendForwardFilter extends ZuulFilter {
 	public Object run() {
 		try {
 			RequestContext ctx = RequestContext.getCurrentContext();
-			String path = (String) ctx.get("forward.to");
+			String path = (String) ctx.get(FORWARD_TO_KEY);
 			RequestDispatcher dispatcher = ctx.getRequest().getRequestDispatcher(path);
 			if (dispatcher != null) {
 				ctx.set(SEND_FORWARD_FILTER_RAN, true);

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/filters/route/SimpleHostRoutingFilter.java

@@ -19,7 +19,6 @@ package org.springframework.cloud.netflix.zuul.filters.route;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.URL;
-import java.nio.charset.Charset;
 import java.security.SecureRandom;
 import java.security.cert.CertificateException;
 import java.security.cert.X509Certificate;
@@ -36,6 +35,8 @@ import javax.net.ssl.TrustManager;
 import javax.net.ssl.X509TrustManager;
 import javax.servlet.http.HttpServletRequest;
 
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import org.apache.http.Header;
 import org.apache.http.HttpHost;
 import org.apache.http.HttpRequest;
@@ -80,11 +81,22 @@ import com.netflix.zuul.ZuulFilter;
 import com.netflix.zuul.constants.ZuulConstants;
 import com.netflix.zuul.context.RequestContext;
 
-import lombok.extern.apachecommons.CommonsLog;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.HTTPS_SCHEME;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.HTTP_SCHEME;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.ROUTE_TYPE;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.SIMPLE_HOST_ROUTING_FILTER_ORDER;
 
-@CommonsLog
+/**
+ * Route {@link ZuulFilter} that sends requests to predetermined URLs via apache {@link HttpClient}.
+ * URLs are found in {@link RequestContext#getRouteHost()}.
+ *
+ * @author Spencer Gibb
+ * @author Dave Syer
+ */
 public class SimpleHostRoutingFilter extends ZuulFilter {
 
+	private static final Log log = LogFactory.getLog(SimpleHostRoutingFilter.class);
+
 	private static final DynamicIntProperty SOCKET_TIMEOUT = DynamicPropertyFactory
 			.getInstance()
 			.getIntProperty(ZuulConstants.ZUUL_HOST_SOCKET_TIMEOUT_MILLIS, 10000);
@@ -148,12 +160,12 @@ public class SimpleHostRoutingFilter extends ZuulFilter {
 
 	@Override
 	public String filterType() {
-		return "route";
+		return ROUTE_TYPE;
 	}
 
 	@Override
 	public int filterOrder() {
-		return 100;
+		return SIMPLE_HOST_ROUTING_FILTER_ORDER;
 	}
 
 	@Override
@@ -212,13 +224,13 @@ public class SimpleHostRoutingFilter extends ZuulFilter {
 
 			RegistryBuilder<ConnectionSocketFactory> registryBuilder = RegistryBuilder
 					.<ConnectionSocketFactory> create()
-					.register("http", PlainConnectionSocketFactory.INSTANCE);
+					.register(HTTP_SCHEME, PlainConnectionSocketFactory.INSTANCE);
 			if (this.sslHostnameValidationEnabled) {
-				registryBuilder.register("https",
+				registryBuilder.register(HTTPS_SCHEME,
 						new SSLConnectionSocketFactory(sslContext));
 			}
 			else {
-				registryBuilder.register("https", new SSLConnectionSocketFactory(
+				registryBuilder.register(HTTPS_SCHEME, new SSLConnectionSocketFactory(
 						sslContext, NoopHostnameVerifier.INSTANCE));
 			}
 			final Registry<ConnectionSocketFactory> registry = registryBuilder.build();

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/filters/support/FilterConstants.java

+/*
+ * Copyright 2013-2017 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package org.springframework.cloud.netflix.zuul.filters.support;
+
+import com.netflix.zuul.ZuulFilter;
+import org.springframework.cloud.netflix.zuul.filters.pre.DebugFilter;
+import org.springframework.cloud.netflix.zuul.filters.pre.Servlet30WrapperFilter;
+import org.springframework.cloud.netflix.zuul.filters.route.SendForwardFilter;
+
+/**
+ * @author Spencer Gibb
+ */
+public interface FilterConstants {
+
+	// KEY constants -----------------------------------
+
+	/**
+	 * Zuul {@link com.netflix.zuul.context.RequestContext} key for use in {@link org.springframework.cloud.netflix.zuul.filters.route.SendForwardFilter}
+	 */
+	String FORWARD_TO_KEY = "forward.to";
+
+	/**
+	 * Zuul {@link com.netflix.zuul.context.RequestContext} key for use in TODO: determine use
+	 */
+	String PROXY_KEY = "proxy";
+
+	/**
+	 * Zuul {@link com.netflix.zuul.context.RequestContext} key for use in {@link org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter}
+	 */
+	String REQUEST_ENTITY_KEY = "requestEntity";
+
+	/**
+	 * Zuul {@link com.netflix.zuul.context.RequestContext} key for use in TODO: determine use
+	 */
+	String REQUEST_URI_KEY = "requestURI";
+
+	/**
+	 * Zuul {@link com.netflix.zuul.context.RequestContext} key for use in {@link org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter}
+	 */
+	String RETRYABLE_KEY = "retryable";
+
+	/**
+	 * Zuul {@link com.netflix.zuul.context.RequestContext} key for use in {@link org.springframework.cloud.netflix.zuul.filters.post.SendResponseFilter}
+	 */
+	String ROUTING_DEBUG_KEY = "routingDebug";
+
+	/**
+	 * Zuul {@link com.netflix.zuul.context.RequestContext} key for use in {@link org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter}
+	 */
+	String SERVICE_ID_KEY = "serviceId";
+
+	// ORDER constants -----------------------------------
+
+	/**
+	 * Filter Order for {@link DebugFilter#filterOrder()}
+	 */
+	int DEBUG_FILTER_ORDER = 1;
+
+	/**
+	 * Filter Order for {@link org.springframework.cloud.netflix.zuul.filters.pre.FormBodyWrapperFilter#filterOrder()}
+	 */
+	int FORM_BODY_WRAPPER_FILTER_ORDER = -1;
+
+	/**
+	 * Filter Order for {@link org.springframework.cloud.netflix.zuul.filters.pre.PreDecorationFilter}
+	 */
+	int PRE_DECORATION_FILTER_ORDER = 5;
+
+	/**
+	 * Filter Order for {@link org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter#filterOrder()}
+	 */
+	int RIBBON_ROUTING_FILTER_ORDER = 10;
+
+	/**
+	 * Filter Order for {@link org.springframework.cloud.netflix.zuul.filters.post.SendErrorFilter#filterOrder()}
+	 */
+	int SEND_ERROR_FILTER_ORDER = 0;
+
+	/**
+	 * Filter Order for {@link SendForwardFilter#filterOrder()}
+	 */
+	int SEND_FORWARD_FILTER_ORDER = 500;
+
+	/**
+	 * Filter Order for {@link org.springframework.cloud.netflix.zuul.filters.post.SendResponseFilter#filterOrder()}
+	 */
+	int SEND_RESPONSE_FILTER_ORDER = 1000;
+
+	/**
+	 * Filter Order for {@link org.springframework.cloud.netflix.zuul.filters.route.SimpleHostRoutingFilter#filterOrder()}
+	 */
+	int SIMPLE_HOST_ROUTING_FILTER_ORDER = 100;
+
+	/**
+	 * filter order for {@link Servlet30WrapperFilter#filterOrder()}
+	 */
+	int SERVLET_30_WRAPPER_FILTER_ORDER = -2;
+
+	/**
+	 * filter order for {@link org.springframework.cloud.netflix.zuul.filters.pre.ServletDetectionFilter#filterOrder()}
+	 */
+	int SERVLET_DETECTION_FILTER_ORDER = -3;
+
+	// Zuul Filter TYPE constants -----------------------------------
+
+	/**
+	 * {@link ZuulFilter#filterType()} error type.
+	 */
+	String ERROR_TYPE = "error";
+
+	/**
+	 * {@link ZuulFilter#filterType()} post type.
+	 */
+	String POST_TYPE = "post";
+
+	/**
+	 * {@link ZuulFilter#filterType()} pre type.
+	 */
+	String PRE_TYPE = "pre";
+
+	/**
+	 * {@link ZuulFilter#filterType()} route type.
+	 */
+	String ROUTE_TYPE = "route";
+
+	// OTHER constants -----------------------------------
+
+	/**
+	 * Zuul {@link com.netflix.zuul.context.RequestContext} key for use in {@link org.springframework.cloud.netflix.zuul.filters.route.SendForwardFilter}
+	 */
+	String FORWARD_LOCATION_PREFIX = "forward:";
+
+	/**
+	 * default http port
+	 */
+	int HTTP_PORT = 80;
+
+	/**
+	 * default https port
+	 */
+	int HTTPS_PORT = 443;
+
+	/**
+	 * http url scheme
+	 */
+	String HTTP_SCHEME = "http";
+
+	/**
+	 * https url scheme
+	 */
+	String HTTPS_SCHEME = "https";
+
+	// HEADER constants -----------------------------------
+
+	/**
+	 * X-* Header for the matching url. Used when routes use a url rather than serviceId
+	 */
+	String SERVICE_HEADER = "X-Zuul-Service";
+
+	/**
+	 * X-* Header for the matching serviceId
+	 */
+	String SERVICE_ID_HEADER = "X-Zuul-ServiceId";
+
+	/**
+	 * X-Forwarded-For Header
+	 */
+	String X_FORWARDED_FOR_HEADER = "X-Forwarded-For";
+
+	/**
+	 * X-Forwarded-Host Header
+	 */
+	String X_FORWARDED_HOST_HEADER = "X-Forwarded-Host";
+
+	/**
+	 * X-Forwarded-Prefix Header
+	 */
+	String X_FORWARDED_PREFIX_HEADER = "X-Forwarded-Prefix";
+
+	/**
+	 * X-Forwarded-Port Header
+	 */
+	String X_FORWARDED_PORT_HEADER = "X-Forwarded-Port";
+
+	/**
+	 * X-Forwarded-Proto Header
+	 */
+	String X_FORWARDED_PROTO_HEADER = "X-Forwarded-Proto";
+
+	/**
+	 * X-Zuul-Debug Header
+	 */
+	String X_ZUUL_DEBUG_HEADER = "X-Zuul-Debug-Header";
+}

spring-cloud-netflix-core/src/test/java/org/springframework/cloud/netflix/zuul/filters/post/SendResponseFilterTests.java

@@ -17,12 +17,8 @@
 package org.springframework.cloud.netflix.zuul.filters.post;
 
 import java.io.ByteArrayInputStream;
-import javax.servlet.http.HttpServletRequest;
 
-import com.netflix.config.ConfigurationManager;
-import com.netflix.zuul.constants.ZuulConstants;
-import com.netflix.zuul.context.Debug;
-import com.netflix.zuul.context.RequestContext;
+import javax.servlet.http.HttpServletRequest;
 
 import org.junit.After;
 import org.junit.Before;
@@ -33,9 +29,15 @@ import org.springframework.mock.web.MockHttpServletRequest;
 import org.springframework.mock.web.MockHttpServletResponse;
 import org.springframework.web.util.WebUtils;
 
+import com.netflix.config.ConfigurationManager;
+import com.netflix.zuul.constants.ZuulConstants;
+import com.netflix.zuul.context.Debug;
+import com.netflix.zuul.context.RequestContext;
+
 import static org.hamcrest.Matchers.equalTo;
 import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.X_ZUUL_DEBUG_HEADER;
 
 /**
  * @author Spencer Gibb
@@ -76,7 +78,7 @@ public class SendResponseFilterTests {
 		filter.run();
 
 		String debugHeader = RequestContext.getCurrentContext().getResponse()
-				.getHeader("X-Zuul-Debug-Header");
+				.getHeader(X_ZUUL_DEBUG_HEADER);
 		assertThat("wrong debug header", debugHeader, equalTo("[[[test]]]"));
 	}
 
@@ -129,4 +131,4 @@ public class SendResponseFilterTests {
 		return filter;
 	}
 
-}
+}
\ No newline at end of file

spring-cloud-netflix-core/src/test/java/org/springframework/cloud/netflix/zuul/filters/pre/PreDecorationFilterTests.java

@@ -39,6 +39,9 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.MockitoAnnotations.initMocks;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.FORWARD_TO_KEY;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.REQUEST_URI_KEY;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.SERVICE_ID_KEY;
 
 /**
  * @author Dave Syer
@@ -80,13 +83,13 @@ public class PreDecorationFilterTests {
 
 	@Test
 	public void skippedIfServiceIdSet() throws Exception {
-		RequestContext.getCurrentContext().set("serviceId", "myservice");
+		RequestContext.getCurrentContext().set(SERVICE_ID_KEY, "myservice");
 		assertEquals(false, this.filter.shouldFilter());
 	}
 
 	@Test
 	public void skippedIfForwardToSet() throws Exception {
-		RequestContext.getCurrentContext().set("forward.to", "myconteext");
+		RequestContext.getCurrentContext().set(FORWARD_TO_KEY, "myconteext");
 		assertEquals(false, this.filter.shouldFilter());
 	}
 
@@ -179,7 +182,7 @@ public class PreDecorationFilterTests {
 				new ZuulRoute("foo", "/foo/**", "foo", null, false, null, null));
 		this.filter.run();
 		RequestContext ctx = RequestContext.getCurrentContext();
-		assertEquals("/foo/1", ctx.get("requestURI"));
+		assertEquals("/foo/1", ctx.get(REQUEST_URI_KEY));
 		assertEquals("localhost", ctx.getZuulRequestHeaders().get("x-forwarded-host"));
 		assertEquals("80", ctx.getZuulRequestHeaders().get("x-forwarded-port"));
 		assertEquals("http", ctx.getZuulRequestHeaders().get("x-forwarded-proto"));
@@ -202,7 +205,7 @@ public class PreDecorationFilterTests {
 				new ZuulRoute("foo", "/foo/**", "foo", null, false, null, null));
 		this.filter.run();
 		RequestContext ctx = RequestContext.getCurrentContext();
-		assertEquals("/foo/1", ctx.get("requestURI"));
+		assertEquals("/foo/1", ctx.get(REQUEST_URI_KEY));
 		assertEquals("localhost", ctx.getZuulRequestHeaders().get("x-forwarded-host"));
 		assertEquals("80", ctx.getZuulRequestHeaders().get("x-forwarded-port"));
 		assertEquals("http", ctx.getZuulRequestHeaders().get("x-forwarded-proto"));
@@ -223,7 +226,7 @@ public class PreDecorationFilterTests {
 				new ZuulRoute("foo", "/api/foo/**", "foo", null, false, null, null));
 		this.filter.run();
 		RequestContext ctx = RequestContext.getCurrentContext();
-		assertEquals("/api/foo/1", ctx.get("requestURI"));
+		assertEquals("/api/foo/1", ctx.get(REQUEST_URI_KEY));
 		assertEquals("localhost", ctx.getZuulRequestHeaders().get("x-forwarded-host"));
 		assertEquals("80", ctx.getZuulRequestHeaders().get("x-forwarded-port"));
 		assertEquals("http", ctx.getZuulRequestHeaders().get("x-forwarded-proto"));
@@ -243,7 +246,7 @@ public class PreDecorationFilterTests {
 				new ZuulRoute("foo", "/foo/**", "foo", null, false, null, null));
 		this.filter.run();
 		RequestContext ctx = RequestContext.getCurrentContext();
-		assertEquals("/foo/1", ctx.get("requestURI"));
+		assertEquals("/foo/1", ctx.get(REQUEST_URI_KEY));
 		assertEquals("localhost", ctx.getZuulRequestHeaders().get("x-forwarded-host"));
 		assertEquals("80", ctx.getZuulRequestHeaders().get("x-forwarded-port"));
 		assertEquals("http", ctx.getZuulRequestHeaders().get("x-forwarded-proto"));
@@ -263,7 +266,7 @@ public class PreDecorationFilterTests {
 				new ZuulRoute("foo", "/api/foo/**", "foo", null, false, null, null));
 		this.filter.run();
 		RequestContext ctx = RequestContext.getCurrentContext();
-		assertEquals("/api/foo/1", ctx.get("requestURI"));
+		assertEquals("/api/foo/1", ctx.get(REQUEST_URI_KEY));
 		assertEquals("localhost", ctx.getZuulRequestHeaders().get("x-forwarded-host"));
 		assertEquals("80", ctx.getZuulRequestHeaders().get("x-forwarded-port"));
 		assertEquals("http", ctx.getZuulRequestHeaders().get("x-forwarded-proto"));
@@ -284,7 +287,7 @@ public class PreDecorationFilterTests {
 				new ZuulRoute("foo", "/foo/**", "foo", null, false, null, null));
 		this.filter.run();
 		RequestContext ctx = RequestContext.getCurrentContext();
-		assertEquals("/foo/1", ctx.get("requestURI"));
+		assertEquals("/foo/1", ctx.get(REQUEST_URI_KEY));
 		assertEquals("localhost", ctx.getZuulRequestHeaders().get("x-forwarded-host"));
 		assertEquals("80", ctx.getZuulRequestHeaders().get("x-forwarded-port"));
 		assertEquals("http", ctx.getZuulRequestHeaders().get("x-forwarded-proto"));
@@ -303,7 +306,7 @@ public class PreDecorationFilterTests {
 				new ZuulRoute("foo", "/foo/**", null, "forward:/foo", true, null, null));
 		this.filter.run();
 		RequestContext ctx = RequestContext.getCurrentContext();
-		assertEquals("/foo/1", ctx.get("forward.to"));
+		assertEquals("/foo/1", ctx.get(FORWARD_TO_KEY));
 	}
 
 	@Test
@@ -313,7 +316,7 @@ public class PreDecorationFilterTests {
 				new ZuulRoute("foo", "/foo/**", null, "forward:/bar", false, null, null));
 		this.filter.run();
 		RequestContext ctx = RequestContext.getCurrentContext();
-		assertEquals("/bar/foo/1", ctx.get("forward.to"));
+		assertEquals("/bar/foo/1", ctx.get(FORWARD_TO_KEY));
 	}
 
 	@Test
@@ -324,7 +327,7 @@ public class PreDecorationFilterTests {
 		this.routeLocator.addRoute("/foo/**", "foo");
 		this.filter.run();
 		RequestContext ctx = RequestContext.getCurrentContext();
-		assertEquals("/1", ctx.get("requestURI"));
+		assertEquals("/1", ctx.get(REQUEST_URI_KEY));
 		assertEquals("localhost", ctx.getZuulRequestHeaders().get("x-forwarded-host"));
 		assertEquals("http", ctx.getZuulRequestHeaders().get("x-forwarded-proto"));
 		assertEquals("/api/foo", ctx.getZuulRequestHeaders().get("x-forwarded-prefix"));
@@ -343,7 +346,7 @@ public class PreDecorationFilterTests {
 
 		this.filter.run();
 		RequestContext ctx = RequestContext.getCurrentContext();
-		assertEquals("/api/bar/1", ctx.get("forward.to"));
+		assertEquals("/api/bar/1", ctx.get(FORWARD_TO_KEY));
 	}
 
 	@Test
@@ -361,7 +364,7 @@ public class PreDecorationFilterTests {
 
 		this.filter.run();
 		RequestContext ctx = RequestContext.getCurrentContext();
-		assertEquals("/special/api/bar/1", ctx.get("forward.to"));
+		assertEquals("/special/api/bar/1", ctx.get(FORWARD_TO_KEY));
 	}
 
 	@Test
@@ -380,7 +383,7 @@ public class PreDecorationFilterTests {
 
 		this.filter.run();
 
-		assertEquals("/api/bar/1", ctx.get("forward.to"));
+		assertEquals("/api/bar/1", ctx.get(FORWARD_TO_KEY));
 	}
 
 	@Test
@@ -402,7 +405,7 @@ public class PreDecorationFilterTests {
 
 		this.filter.run();
 
-		assertEquals("/special/api/bar/1", ctx.get("forward.to"));
+		assertEquals("/special/api/bar/1", ctx.get(FORWARD_TO_KEY));
 	}
 
 	@Test
@@ -425,7 +428,7 @@ public class PreDecorationFilterTests {
 
 		this.filter.run();
 
-		assertEquals("/special/api/bar/1", ctx.get("forward.to"));
+		assertEquals("/special/api/bar/1", ctx.get(FORWARD_TO_KEY));
 	}
 
 	@Test
@@ -545,7 +548,7 @@ public class PreDecorationFilterTests {
 		this.routeLocator.addRoute("/foo/**", "foo");
 		RequestContext ctx = RequestContext.getCurrentContext();
 		this.filter.run();
-		String decodedRequestURI = (String) ctx.get("requestURI");
+		String decodedRequestURI = (String) ctx.get(REQUEST_URI_KEY);
 		assertTrue(decodedRequestURI.equals("/oléדרעק"));
 	}
 

spring-cloud-netflix-core/src/test/java/org/springframework/cloud/netflix/zuul/filters/route/SendForwardFilterTests.java

@@ -28,6 +28,7 @@ import com.netflix.zuul.context.RequestContext;
 
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
+import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.FORWARD_TO_KEY;
 
 /**
  * @author Dave Syer
@@ -56,7 +57,7 @@ public class SendForwardFilterTests {
 		RequestContext context = new RequestContext();
 		context.setRequest(request);
 		context.setResponse(new MockHttpServletResponse());
-		context.set("forward.to", "/foo");
+		context.set(FORWARD_TO_KEY, "/foo");
 		RequestContext.testSetCurrentContext(context);
 		SendForwardFilter filter = new SendForwardFilter();
 		return filter;